1. Field of the Invention
The present invention relates to a method of recording and/or reproducing information on and/or from an optical record medium such as optical card and optical disk, and more particularly relates to a method of recording and/or reproducing information on and/or from a plurality of different data record regions on the same optical record medium in order to positively record and/or reproduce the information.
2. Description of the Related Art
In case of using an optical record medium such as an optical card, when a surface of a data record area is injured or stained, it is sometimes impossible to read out the data recorded in the data record region. In order to record and/or reproduce the data in positive manner, there have been proposed various recording and/or reproducing methods. For instance, there has been proposed an error correction method in which an error in a reproduced signal due to the injury or stain of the surface of the data record region is corrected in accordance with a predetermined error correction rule. It is further proposed to record the same data in different data record regions on the same optical record medium. There is a limitation in increasing the reliability of the error correction, so that in addition to the error correction, the duplicate recording of the data in different data record regions is utilized.
In a known method of recording the same data in different data record regions on the same optical card, there are provided a plurality of directory data record regions and a plurality of actual data record regions on the same optical card and directory data and actual data constituting the information are recorded on two different directory regions and two different actual data record regions, respectively.
FIG. 1 is a plan view showing an example of an optical card which may be used in the above mentioned duplicate recording method. As illustrated in FIG. 1, the optical card includes first and second directory data record regions 11 and 13 and first and second actual data record regions 12 and 14. After the actual data of information are recorded in the first actual data record region 12, the directory data indicating the position in the first actual data record region in which the relevant data are recorded are recorded in the first directory data record region 11, and similarly, after the same actual data are recorded in the second actual data record region 14, the directory data denoting a position in the second actual data record region in which the actual data are recorded are recorded in the second directory data record region 13. In this manner, in the known method of recording the information on the optical card, the directory data recorded in the different directory record regions have no relation to each other. That is to say, in each directory record region, only the directory data for managing the actual data recorded in the related actual data record region are recorded. Therefore, the improvement in the data record reliability and the efficiency in the data reproducing could not be attained optimally.
FIG. 2 is a flow chart representing a known method of reproducing the information which has been recorded on the optical card in the manner explained above. In a step S1, the directory data recorded in the first directory data record region 11 are read out. Then, in a step S2, it is checked whether the directory data have been correctly read out or not. In the step S2, when the directory data have been confirmed to be read out correctly, then in a step S3, the actual data recorded in the first actual data record region 12 are read out under the control of the directory data. Next, in a step S4, it is checked whether the actual data have been read out correctly or not. When it is confirmed that the actual data have been read out correctly, the reproducing operation is completed.
However, if the directory data have not been correctly read out of the first directory data record region 11 in the step S2, then the directory data recorded in the second directory data record region 13 is read out in a step S5. After that, in a step S6, it is checked whether the directory data can be correctly read out of the second directory data record region 13 or not. If it is confirmed that the directory data have been correctly read out of the second directory data record region 13, then in a step S7 the actual data recorded in the second actual data record region 14 are read out under the control of the directory data read out of the second directory data record region 13, and then in a step S8 it is further checked whether the actual data have been correctly read out or not.
In the step S6, it is confirmed that the directory data could not be correctly read out of the second directory data record region 13, then it is judged the process is ended with an error message in a step S9.
In the known method of recording and/or reproducing the information on and/or from the optical card, if the directory data recorded in the first directory data record region 11 could not be read out correctly, the directory data are read out of the second directory data record region 13, and the actual data are read out of the second actual data record region 14 in accordance with the directory data read out of the second directory data record region. In this case, if the actual data could not be read correctly out of the second actual data record region 14 due to the injury or stain of the second actual data record region, it is no longer possible to read the actual data out of the optical card. Further, even when the directory data are correctly read out of the first directory data record region 11, the actual data could not be read out the optical card if the first actual data record region 12 is injured.